From: Hans Holmberg <hans.holmberg@cnexlabs.com>
Date: Fri, 13 Oct 2017 14:46:39 +0200
Subject: [PATCH] lightnvm: pblk: shut down gc gracefully during exit
Git-commit: 1edebacf8b736774d2f160512aec721f47e1f5ac
Patch-mainline: v4.15-rc1
References: bsc#1104967,FATE#325924
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

Shut down the GC workqueues and tasks in the right order.

Signed-off-by: Hans Holmberg <hans.holmberg@cnexlabs.com>
Signed-off-by: Matias Bjørling <m@bjorling.me>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Acked-by: Hannes Reinecke <hare@suse.com>
---
 drivers/lightnvm/pblk-gc.c | 20 ++++++++++++--------
 1 file changed, 12 insertions(+), 8 deletions(-)

diff --git a/drivers/lightnvm/pblk-gc.c b/drivers/lightnvm/pblk-gc.c
index 4bac9e1531f5..e00e5a0743e9 100644
--- a/drivers/lightnvm/pblk-gc.c
+++ b/drivers/lightnvm/pblk-gc.c
@@ -422,10 +422,15 @@ void pblk_gc_kick(struct pblk *pblk)
 {
 	struct pblk_gc *gc = &pblk->gc;
 
-	wake_up_process(gc->gc_ts);
 	pblk_gc_writer_kick(gc);
 	pblk_gc_reader_kick(gc);
-	mod_timer(&gc->gc_timer, jiffies + msecs_to_jiffies(GC_TIME_MSECS));
+
+	/* If we're shutting down GC, let's not start it up again */
+	if (gc->gc_enabled) {
+		wake_up_process(gc->gc_ts);
+		mod_timer(&gc->gc_timer,
+			  jiffies + msecs_to_jiffies(GC_TIME_MSECS));
+	}
 }
 
 static void pblk_gc_timer(unsigned long data)
@@ -630,9 +635,6 @@ void pblk_gc_exit(struct pblk *pblk)
 {
 	struct pblk_gc *gc = &pblk->gc;
 
-	flush_workqueue(gc->gc_reader_wq);
-	flush_workqueue(gc->gc_line_reader_wq);
-
 	gc->gc_enabled = 0;
 	del_timer_sync(&gc->gc_timer);
 	pblk_gc_stop(pblk, 1);
@@ -640,15 +642,17 @@ void pblk_gc_exit(struct pblk *pblk)
 	if (gc->gc_ts)
 		kthread_stop(gc->gc_ts);
 
+	if (gc->gc_reader_ts)
+		kthread_stop(gc->gc_reader_ts);
+
+	flush_workqueue(gc->gc_reader_wq);
 	if (gc->gc_reader_wq)
 		destroy_workqueue(gc->gc_reader_wq);
 
+	flush_workqueue(gc->gc_line_reader_wq);
 	if (gc->gc_line_reader_wq)
 		destroy_workqueue(gc->gc_line_reader_wq);
 
 	if (gc->gc_writer_ts)
 		kthread_stop(gc->gc_writer_ts);
-
-	if (gc->gc_reader_ts)
-		kthread_stop(gc->gc_reader_ts);
 }
-- 
2.12.3